Needle drive mechanism for bag sewing machines



Sept. 27, 1966 HANS-OTTO KELLER ETAL 3,274,963

NEEDLE DRIVE MECHANISM FOR BAG SEWING MACHINES Filed Dec. 1, 1964 .4 1-1-0? EYS United States Patent firm Filed Dec. 1, 1964, Ser. No. 415,111 Claims priority, application Germany, Feb. 8, 1964, M 59 859 6 Claims. cl. 112-413 Our invention relates to machines for making trunks, bags or the like in which the side walls are sewed to the bottoms and to the covers, and the principal object thereof is to provide a simple, novel and efficient sewing machine for this purpose, having certain novel features of construction, and novel combinations of parts hereinafter described.

In the manufacture of trunks, including those used for air travel, carrying cases, bags, or the like, in which the side walls are joined to the bottoms and to the covers by stitching, use is generally made of chain-stitching machines to join the parts together. Such machines are usually provided with a horizontally projecting carrier arm which contains the driving means for the sewing and feeding mechanism, and which also serves as a support for the trunk that is to be stitched and upon which the trunk is guided during said stitching. Such machines are especially suitable for the production of trunks with rounded edges and corners, i.e., the so-called all-round trunks, for which the carrier arm provides a convenient guide for easy feeding.

Although these machines have been favorably received and have given good service, they had the disadvantage of being able to operate upon only relatively large trunks or the like because the driving means which are mounted in the carrier arm for the actuation of one of two needles occupied considerable space of great depth so that the carrier arm which was to serve as a guide must be equally large. F or this reason it has heretofore not been possible to sew smaller trunks or shopping bags upon such machines, although with the increased demand for such smaller containers during recent years, these machines should be redesigned most suitably for that purpose.

One object of our present invention therefore is to provide a new construction of the driving means in the carrier arm which permits the height of the arm to be reduced, and the head to be brought down proportionately lower so as to permit trunks, bags and other containers of small size to be guided upon said arm completely around the head while being stitched.

Another object of our invention is the provision that the actuating members for the sewing needle and for the auxiliary needle will be guided from both sides, such bilateral guideways permitting the machine to be driven at high speeds.

An example of our invention is shown in the accompanying drawing in which:

FIG. 1 is a vertical longitudinal section through the carrier arm and head;

FIG. 2 is a horizontal section through the head of the carrier arm; and

FIG. 3 is a vertical transverse section through the head on the line III-III, FIG. 1.

The general construction of a machine of this kind is well known. The stationary housing 2 is fastened by screws 2a to the front end of the carrier arm 4. The housing 2 contains the transport block 6 which together with all the mechanism carried by it is able to swing in a horizontal direction with the conventional rock shaft 8. On the transport block 6 the driving lever 10 for the needle bar 22 of the needle or needles 1'2, 12' is pivotally mounted at 14, while a similar driving lever 18 for the cast-01f needle bar 20 (FIG. 3), is pivotally mounted on stud 16. This swinging movement is delivered to the needle bar 22 carrying needles 12, 12, thereby effecting feeding movement of the workpiece, as indicated by the dotted position of the needle 12 in FIG. 3.

The levers 10 and 18 are forloshaped so that they will have a firm bearing support. Their angular forms in nested relation to each other as shown in FIG. 2 insures a compact form of driving mechanism, both in width and in depth. This construction also permits both the needle bar 22 and the cast-off needle bar 20 to be made hollow to reduce the weight and mass of these moving parts, thereby permitting their operation at higher speeds. Such high speed operation is also facilitated by the means for connecting the levers 10 and 18 with the needle bar 22 and immediately behind it with the cast-off needle bar 20 in a known manner, and by the provision of the gnideway 18 (FIG. 1) for the needle bar 22 at the upper end of the cast-off needle bar, forming a very compact structure.

To provide pivotal mountings for the swinging levers 10 and 18 on the studs 14 and16, the transport block 6 is provided with vertical threaded boreholes 24 (FIG. 1) which intersect the transverse stud-supporting bores, for receiving pointed set-screws 26 to seat in recesses 28 (FIG. 2) for holding the studs 14 and 16 firmly in place against lateral movement in their bores. In a similar manner the needle bar 22 and the cast-off needle bar 20 are connected by means of lashes 30 and 32 with the ends of their respective operating levers 10 and 18 through crankpins 10' and 18". The lashes carry pivot pins 34 and 36 guided in slots 38 and 40 of the transport block 6, the pins being held in place by set screws 50 (FIG. 3) similar to those 26 which hold the studs 14 and 16 in place. The angular levers 10 and 18 are actuated in a well known manner by means of reciprocating bars 42 and 44 pivotally connected to the forked ends of the levers.

An important feature of this invention is the reduced height of the carrier block 2 which has been reduced from its previous height of about 185 mm. to mm. or less, so that smaller trunks and bags or the like of small dimensions can be conveniently sewed on the machine.

We claim:

1. In a machine for making trunks, bags or the like in which the side walls thereof are sewed to the bottoms and to the covers, said machine having a carrier arm contain ing reciprocable driving means for the sewing and feeding mechanism; a stationary housing secured to the end of the carrier arm; a transport block horizontally rockably mounted in said housing; said mechanism including sewing and feeding needle bars reciprocably mounted in said block; and angular driving levers for said bars pivotally mounted on said block each having a relatively short downwardly extending arm connected to said driving means respectively and having a relatively long horizontal arm connected with its related bar, whereby the said housing will have a minimum height to permit sewing of relatively small trunks and bags.

2. In a machine for making trunks, bags or the like in which the side walls thereof are sewed to the bottoms and to the covers, said machine having a carrier arm containing reciprocable driving means for the sewing and feeding mechanism; a stationary housing secured to the end of the carrier arm; a transport block horizontally rockably mounted in said housing; said mechanism including sewing and feeding needle bars reciprocably mounted in said block; and angular driving levers for said bars pivotally mounted on said block each having a relatively short downwardly extending arm connected to said driving means respectively and having a relatively long horizontal arm connected with its related bar, whereby the said housing will have a minimum height to permit sewing of relatively small trunks and bags, said driving levers being fork-shaped and nested together with the transport block disposed between the legs of the levers respectively; each lever being pivotally supported at each side of the block, thereby minimizing the width and depth of the mechanism.

3. In a machine for making trunks, bags or the like in which the side walls thereof are sewed to the bottoms and to the covers, said machine having a carrier arm containing reciprocable driving means for the sewing and feeding mechanism; a stationary housing secured to the end of the carrier arm; a transport block horizontally rockably mounted in said housing; said mechanism including sewing and feeding needle bars reciprocably mounted in said block; and angular driving levers for said bars pivotally mounted on said block each having a relatively short downwardly extending arm connected to said driving means respectively and having a relatively long horizontal arm connected with its related bar, whereby the said housing will have a minimum height to permit sewing of relatively small trunks and bags, the sewing and feeding needle bars being hollow to effect minimum weight and to permit operation at relatively high speeds.

4. In a machine for making trunks, bags or the like in which the side walls thereof are sewed to the bottoms and to the covers, said machine having a carrier arm containing reciprocable driving means for the sewing and feeding mechanism; a stationary housing secured to the end of the carrier arm; a transport block horizontally rockably mounted in said housing; said mechanism including sewing and feeding needle bars reciprocably mounted in said block; and angular driving levers for said bars pivotally mounted on said block each having a relatively short downwardly extending arm connected to said driving means respectively and having a relatively long horizontal arm connected with its related bar, whereby the said housing will have a minimum height to permit sewing of relatively small trunks and bags, said housing having an overall height of less than mm.

5. In a machine for making trunks, bags or the like in which the side walls thereof are sewed to the bottoms and to the covers, said machine having a carrier arm containing reciprocable driving means for the sewing and feeding mechanism; a stationary housing secured to the end of the carrier arm; a transport block horizontally rockably mounted in said housing; said mechanism including sewing and feeding needle hollow bars reciprocably mounted in said block; angular driving levers for said bars pivotally mounted on said block each having a relatively short downwardly extending arm connected to said driving means respectively and having a relatively long horizontal arm connected with its related bar, said driving levers being fork-shaped and nested together with the transport block disposed between the legs of the levers respectively; each lever being pivotally supported at each side of the block, whereby the said housing may have a minimum height to permit sewing of relatively small trunks and bags.

6. In a machine as set forth in claim 5, said housing having an overall height of less than 150 mm.

References Cited by the Examiner UNITED STATES PATENTS 1,162,696 11/:1915 Ierram 112-212 1,443,634 1/1923 M-offatt et al 112213 2,024,802 12/1935 Mitchell 1l2213 X FOREIGN PATENTS 555,230 6/1923 France.

JORDAN FRANKLIN, Primary Examiner.

FRANK I COHEN, Examiner.

H. H. HUNTER, Assistant Examiner. 

1. IN A MACHINE FOR MAKING TRUNKS BAGS, OR THE LIKE IN WHICH THE SIDE WALLS THEREOF ARE SEWED TO THE BOTTOMS AND TO THE COVERS, SAID MACHINE HAVIANG A CARRIER ARM CONTAINING RECIPROCABLE DRIVING MEANS FOR THE SEWING AND FEEDING MECHANISM; A STATIONARY HOUSING SECURED TO THE END OF THE CARRIER ARM; A TRANSPORT BLOCK HORIZONTALLY ROCKABLY MOUNTED IN SAID HOUSING; SAID MECHANISM INCLUDING SEWING AND FEEDING NEEDLE BARS RECIPROCABLY MOUNTED IN 